Centrioles - sites for active RNA synthesis.
Thylakoids - flattened membranous sacs forming the grana of chloroplasts.
Ribosomes - those on chloroplasts are larger (80S) while those in the cytoplasm are smaller (70S).
Lysosomes- optically active at a pH of about 8.5
A thylakoid is a membrane-bound, flattened compartment inside chloroplasts and cyanobacteria. They are the site of the light-dependent reactions of photosynthesis. Thylakoids consist of a thylakoid membrane surrounding a thylakoid lumen.